Why do metals conduct electricity?

Metals conduct electricity because they have delocalised electrons that are free to move through the structure and carry charge.

GCSE Chemistry

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

In more detail

In a metal, the outer electrons are delocalised and form a "sea" of free electrons around positive metal ions. When a voltage is applied, these delocalised electrons drift through the metal, carrying charge — so the metal conducts electricity. The same free electrons also make metals good conductors of heat.

Key points for the exam

  • Metallic bonding: positive ions in a sea of delocalised electrons.
  • The delocalised electrons are free to move and carry charge.
Exam tip: Use "delocalised electrons that are free to move and carry charge" — the standard mark-scheme wording.

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